Steel alloy.



J. W. WEITZENK sEEL ALLOY.

APPLICATION FILED JAN.

STATESv PATENT OFFICE.

- JosErn w.l wEITzENxoRN, or WASHINGTON, PENNsYLvANIA, AssIGNoR To ELECTRIC REDUCTION COMPANY, OF lWASHING'ION, PENNSYLVANIA, A CORPORATION 'OF DELAWARE.

` STEEL ALLoY.

Specication of Letters Patent.

Patented Dee. 10, 1918.

Application iled January 25, 19.18. Serial No. 213,706.

T o all whom it may concern Be it known that I, JOSEPH W. WEITzEN- KoRN, residing at Washington, in the county of Washington and State of Pennsylvania, a citizen of the United States, have invented or discovered certain new and useful Improvements in Steel Alloys, of which improvements the following is a specification. My invention relates to alloys for structural articles made of steel. By such art ticles I 'mean -to include structural steel elements entering into the lmanufacture -of engmes, machines, aeroplanes, marine torpedoes,.etc., which elements, in proportion to strengt their weight, are required to possess great strength and toughness .to resistv repeated stresses of various characters.

The usual steel alloys from which such articles are manufactured, when heated to ahigh temperature and suddenly quenched or cooled, have high ultimate strengths and `elastic limits, but they are exceedingly hard yand brittle.

To toughen such alloys the usual practice is to reheat them in orderv to draw or anneal them. IVhile such prior alloys may be thus toughened, the toughness is attained at avery substantial sacrifice of strength.

The object of my invention is to provide have both great strength Aand toughness, when quenched or cooled from a wide range 0f temperatures, or when drawn or annealed.

My invention proceeds upon my discovery of a steel alloy which will not only have un.- usually great strength when cooled or quenched from a wide hardening range of I temperatures, but will also possess great toughness, and which, when annealed or drawn to further increase its toughness, will decreas but a relatively small amount in The alloy which I discovered, and which is characterized as iust stated, contains not more than about .60% of carbon, from about pounds and its reduction of area L drawing of a steel from such relatively low a steel alloy for such articles which will sults may be obtained witha steel alloy containing about .35% carbon, 1.00% chromium, .15% vanadium, and from about .75% to 1.00% molybdenum.

Standard test specimens of an alloy of the composition just described were subjected to numerous tests to determine its physical properties. These Specimens consisted of 1s inch round bars oil treated from 1600 F., machined to 5.05 inches in diameter, and subsequently ydrawn or annealed from various temperatures. The results of these tests have been carefully plotted on a curve sheet which is reproduced on the accompanying drawing. The. drawing shows the curves for the ultimate strength, elastic limit, percentage reduction of area and percentage of elongation in two inches of the specimens when drawn or annealed from temperatures ranging from about` 500 F. to 1400" F.

There are also shown on the drawing fhe Shore and Brinell hardnesses of the alley when drawn from various temperatures.

It will be observed first that when the steel alloy is drawn from the relatively low temperature of 500o F., its ultimate strength is 250,000 pounds, its elastic limit '225%00 temperature modifies but a slight amount the. tensile strength and usual hardness of high temperature, say 1600 F. Hence it will be seen that the steel alloy nwhich I provide has an unusually high ultimate strength and elastic limit when quenched from a high temperature, and a very high percentage reduction of area when thus treated.

As the drawing temperatures are raised up to 1200 F. to further increase the toughness of the steel there is small loss of ulti-YY the steel when quenched from a relatively Weight, and hence are particularly suitable carbon, 1.00% chromium, .15% vanadium, 10 for structures such as aeroplanes which are and from about .75% to 1.00% molybdenum.

required to be light in weight. In testimony whereof have hereunto set I claim as mly invention: f my hand. 5 1. A steel a oy consisting o not more @111.60% carbon, from` about .50% to 1.50% JOSEPH W' WETZENEORN' chromium, .10% to .50% vanadium, and Witnesses: .50% to 1.25% molybdenum. E. A. LUCAS,

2. A steel alloy consisting of about .35% CLIFTON JAY. 

